setup

$ git init
... configure a remote (git remote add)
... add stuff and commit
$ npm init

Install babel-cli and babel-latest and add the 'build' script babel src -d build to the package.json.

In the same file, we'll need to configure babel:

{
    ...
    "babel": {
        "presets": "latest"
    }
    ...
}

Run npm run build.

The watch package can be used to run the task on file changes. Add a 'dev' script watch 'npm run build'. Note may not work on windows.

jest can also be added to handle tests. Add 'test' task jest.

Add 'file.test.js' and it will be recognized by jest.

import testModule from '.';

test('works'. () => (
    expect(testModule.work()).toBe('hell yeah');
));

Jest can be ran automatically on file updates: jest --watch.

Testing packages locally (npm link)

First run npm link in the developed module folder. Then in the project that uses the module, run npm link <name of the module>. This will create a symbolic link link to the local version.

Don't forget the Readme

prepublish

Add a script name 'prepublish' running the tasks that are required to build the module.

It will be ran before the publish task.

Add a .npmignore containing the list of directories and files to ignore.

src

NPM will ignore files in .gitignoreand files in.npmignore`.

prior to publish

Use your username password to connect npm to npmjs:

$ npm adduser

You are now connected.

Publish

$ npm publish

Scoped packages

It seems to be the new trend, add scope to your package name. Every user of npm has the scope of its username.

If you run npm publish, it will fail miserably with an error:

62 error code E402
63 error You must sign up for private packages : @magnus/send-timings

This is because scoped packages are private by default; that is a billable feature of npm.

This is solved by publishing publicly:

npm publish --access=public

Update existing module

Install 'np', add a task name 'release' executing np to handle the upgrades.